Electric railway-signaling apparatus



(No Model.) 2 Sheets-Sheet 1. O. GASSETT. Electric Railway signa lingApparatus.

No. 233,746. Patented Oct. 26, 1880.

2 Sheets-Sheet 2.

(No Model.)

0. GASSETT. Electric Railway Signaling Apparatus.

No. 233,746. Patented Oct. 26,1880.

N. PETERS, PMOTO-LITHOGRAPHER, WASHINGTON. D G.

UNITED STATES PATENT mace.

OSCAR GASSETT, OF BOSTON, MASSACHUSETTS.

ELECTRIC RAI LWAY-SIGNA LING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 233,746, dated October26, 1880.

Application filed August 10, 1880.

To all whom it may concern:

Be it known that I, OSCAR GASSETT, a citizen of the United States,residing in Boston, in the county of Suffolk and State of Massachusetts,have invented certain new and useful Improvements in Circuits andApparatus for Electric Railway-Signaling, of which the following is aspecification.

My invention relates to that system of automatic electricrailway-signalin g which consists in dividing the whole or a portion ofthe length of a line of railway into signal-sections of any required orconvenient length, (which length corresponds to the minimum interval ofspace which it is desired to preserve between different trains movingupon the same track,)'and in guarding each of said sections by a signalplaced at or near the entrance of such section, which signal is actuatedor controlled by an electro-magnet included in an electric circuitextending the entire length of the signal-section to which itappertains, said electromagnet being, in its turn, controlled throughthe electric circuit by a movable circuit-closer attached to the train.By this means the passage of a train over each successive signalsectioncauses a danger-signal to be exhibited at the entrance of such sectionfrom the time that the train enters it at one end until it leaves it atthe opposite end, when the dangersignal is withdrawn or discontinued,leaving the way clear for the next succeeding train.

It has been found in practice that it is frequently desirable andnecessary to continue a given danger-signal in action after the trainwhich sets it in action has passed off from'the section which the signalis designed to guard until such train has passed over the next sectionin advance or a certain portion thereof, by which means an additionalsecurity is provided, especially upon dangerous portions of the road,such as sharp curves or descending grades.

The object of my invention is to effect this result; and it consists,principally, in a novel arrangement of electric circuits, in which theseveral circuits appertaining to the different signal-sections, insteadof being entirely independent of each other, as in the ordinaryarrangement, are made to act to a certain extent dependently,so thateach circuit is, as heretofore, under the direct control of the trainwhile the latter is traversing its own section,

(No model.)

but, in addition to this, is also indirectly under the control of thetrain through the agency of the next signal-circuit in the series whilethe said train is traversing a certain portion of the nextsignalrsection.

In the accompanying drawings, Figure l is a perspective view of aportionof a line of railway comprising three signal sections, and showing therelation of the several signals to the sections and to the movement oftrains upon the line. Fig. 2 is a diagram showing a signal-section andits accompanying electric circuit and apparatus in a position of rest;and Fig. 3 shows the same in the act oflbeing operated by the passage ofa train.

In Fig. 1,A A ,A A ,andA A represent three successive signal-sections,into which the railway is divided, and these are usually, in prac tice,from one to two miles in length. At the entrance of each signal-sectionin the direction in which the trains move is placed'a signal, as seen atS, S S and S. The particular construction of these signals isimmaterial, as they may be of any of the well-known forms which areemployed for such purposes. I have shown, by preference, a signalconsisting of two vanes or wings at right angles to each other andmounted upon a vertical spindle. One of the vanes is colored andsignifies danger, while the other is white and signifies safety. Bycausing the spindle to turn upon its axis either the white or thecolored "ane may be placed in a position at right angles to the track,so as to be visible to the engineer of an approaching train, while atthe same time the other vane will stand edgewise, so as to bepracticallyinvisible.

In Fig. l the signal S is supposed'to be placed at the initial point ofthe railway, or of the series of signal-sections. The commencement ofthe first section is at the insulated track-splices a a, and it extendsto a pair of similar splices, a a at which point the next signal-sectioncommences, its entrance being guarded by a second signal, S and so onindefinitely.

By an arrangementof electric circuits, which will be hereinafterexplained, a locomotive or train, T, upon entering upon-thesignal-section A A at the end nearest the signal S, causes the signal toassume the position shown, with its colored vane (signifying danger) atright angles to the track, and the signal will remain circuits, whichcontinues the action of a signal-as, for example, not only while a trainis passingfrom a a to a a, but also while it is passing from a a to b asshown in the figure. Therefore, if any accident should occur to stop thetrain T in the position in which it is represented in the figure, thefollowing train is warned, not alone by the signal S which might be toonear to enable the following train to be stopped in time, but, inaddition, by the signal S a mile or more farther back.

The manner in which this result is effected will be best understood byreference to the diagrams, Figs. 2 and 3, which represent thearrangement of electric circuits and apparatus in connection with thesignal-section A A of Fig. 1, with a portion of the adjacent sections oneither side, so as to show the relation between them.

The apparatus about to be described is similar to that upon all theother sections, and the same arrangement is duplicated for a doubletrackrailroad.

Fig. 2 shows the apparatus in a position of rest when no trains are onthe line.

The signal S may be constructed in the manner which has beenhereinbefore described, or in any other suitable or convenient manner,and it may be actuated directly by the armature-lever f of theelectro-magnet s ,-or by a train of wheels impelled by a weight orspring and controlled by the armature-lever, or in any other manner, theonly essential being that it shall be so controlled by theelectro-magnet as to exhibit a safety-signal whenever the said magnet isin its magnetic condition, and a dangersignal whenever it isdemagnetized.

The opposite lines of rails of the signal-section A A are insulated fromthose of the adjacent section in each direction by suitable insulatedsplices a a and a (N, the construction and arrangement of which are wellunderstood and need no detailed description.

Each line of rails is connected together, so as to form a continuouselectric conductor from one end of the section to the other, except at apoint, I), where an insulated splice is inserted in one line of railsonly, the sevcred ends being connected bytthe wires 3 4, which form theterminals of an electro-ma-gnet, 0

At the left-hand end of the signal-section A A is placed a battery, Ethe opposite poles of which are connected by conductors with therespective lines of rails, while at the other or right-hand end of thesection the terminals 6 7 of the signal-magnet s are connected with thesaid lines of rails in a similar manner.

A circuit-breaker, n controlled by an electro-magnet, T is placed in oneof the conductors connecting the battery E with the lines of rails. Theelectro-magnet 0 controlsa similar circuit-breaker, d, which is placedin a local circuit from the battery 0, and includes the electro-magncta", which controls the circuit breaker a of the adjacent section.

When no train is on the line, as in Fig. 2,a constant current from thebattery E traverses the wire 1, the line of rails 2 2, wire 3, electro-ma net 0 wire 4 line of rails 5 5 wire 6 h 7 7 i and signal-magnet sreturning by the wire 7,

opposite line of rails 8 8,'wire 9, circuit-breaker i M, (which isclosed,) and wire 10 to the other pole of the battery. This constantcurrent tends to keep the electromagnetsc and s in a continuouslymagnetic condition; but the electro-magnet c is so constructed that itrequires a much greater strength of current to affect its armature thanis necessary to produce a like efiect upon the signal-magnet .9 This maybe accomplished either by making use of a smaller number of convolutionsof wire in the coils of 0 or by giving an increased ten sion to theretractin g-sprin g of its armature, or in other ways well known tothose skilled in the art.

The effect of this arrangement is, that in the normal condition ofaffairs the constant current traverses both the electro-magnets s and 0the armature of s is attracted, maintaining the signal S in a positionindicating safety, while the armature d of electro-magnet c is drawnback against its back-stop by the retracting-spring. This position .ofthe armature d keeps the local circuit 11 12 of the bat tery 6 closedthrough the electro-magnct 1', which, in turn, keeps the circuit closedwhich traverses the next section from its own battery E. The circuit ofthe battery E of the section under consideration is closed in likemanner by the electro-magnet r of the succeeding section, and so onthrough the entire series.

Thus it will be understood that the interruption of the constant currentof either the battery E or the battery 0 will cause the electro-magnet sto be demagnetized and the signal S to be placed in a position denotingdanger. Such an interruption might occur from a failure of the batteryto act, or from the breaking of a wire or one of the rails of the track,the removal or displacement of a rail, or any similar cause. In any casethe signal immediately assumes a position indicating dau ger.

The manner in which the signals are successively actuated by a niovingtrain is as follows Referring to Fig. 3, suppose a train has enteredupon the signal-section A A and occupies the position indicated by thedotted line at T, or any position between the insulated splices a and W.The wheels and axles of the train form a movable circuit-closer havingno appreciable electric resistance, which forms a connection between thetwo opposite rails of the track. The current from the battery IE willn0w be diverted from the electromagnet 8 and will pass across at T fromthe rail 5 to the rail 8. The electro-magnet s will be demagnetized anda danger-signal exhibited guarding the entrance of the section in therear of the train. The removal of the resistance of the electro-magnet 8caused by thus cutting it out of the circuit greatly increases thestrength of the current in the remaining portion of the circuit,including the electro-magnet c and the magnetism of the latter beingcorrespondingly augmented, it draws its armature forward, breaking thelocal circuit 11 12, wh ch releases the armature a of the localelectro-magnet r, breaking the main circuit of the rearward section, A,and thus exhibiting a danger-signal at the entrance of that sectionalso. This latter signal will continue to be exhibited until the train Thas wholly passed beyond the insulated splice 12 when a connection willbe formed by it between the rails 2 and 8, which will cut out theelectro-magnet c and by a reversal of the previously-described actionrestore the circuit of the section A and withdraw the dangersignal atits entrance, while the danger-signal at S will continue tobeexhibitedin like manner until the train has reached the point b of theadvance section A Thus it will be understood that the dangersignal ofeach section is exhibited during the passage of atrain over that sectionby the shunting of its electro-magnet, and that its exhibition iscontinued during the passage of the train over a portion of the nextadvance section by the interruption of the circuit by means of acircuit-breaker controlled by the train while traversing the lattersection.

The insulated spliceb may be placed at any desired point between a and aaccording to circumstances. In practice it is usually preferable toplace it at a distance from the point a atthe entrance of the sectionequal to the maximum distance required to stop a train after passing thesignal S at full speed, and this will obviously be determined by thecircumstances of the particular location.

I claim as my invention- 1. A railway-signaling circuit consisting ofthe following elements in combination: a continuous line of railsforming an electric conductor from one end of a signal-section to theother, a parallel line of rails of like extent longitudinally andforming a similar conductor, but divided into two sub-sections at anintermediate point, an eleetro-magnet, conductors connecting theadjacent ends of said sub-sections with the respective terminals of thecoils of said electro-magnet, a second electro-magnet, conductorsconnecting the terminals of the two parallel lines of rails at one endof the section with the respective terminals of the coils of thelast-named electro-magnet, a battery, and conductors connecting theopposite poles of said battery with the respective parallel lines ofrails at the other end of the section, substantially as hereinbefore setforth.

2. A series of railway-signaling circuits, each consistingof thefollowing elements in combination: a continuous line of rails forming anelectric conductor-from one end of a signalsection to the other, aparallel line of rails of like extent and forming a similar conductor,but divided into two sub-sections at an intermediate point, anelectro-magnet, conductors connecting the adjacent ends of saidsub-sections with the respective terminals of the coils of saidelectromagnet, a visualsignal, an electro-magnet for actuating orcausing to be actuated the said signal, conductors connecting theterminals of the two parallel lines of rails at one end of the'sectionwith the respective terminals of the coils of the signalactuatingelectro-magnet, a battery, conductors connecting the opposite poles ofsaid battery with the respective parallel lines of rails at the otherend of the section, and a circuitbreaker in one of said conductors underthe control of the intermediate electro-magnet of the next section inthe series, substantially as hereinbefore set forth.

3. The combination, substantially as hereinbefore set forth, of arailway-track divided into two or more signal-sections, a signalingapparatus actuated or controlled by an electro-magnet and placed at theentrance of each one of said signal-sections, a circuit-closercontrolled by a moving train, which acts to exhibit a danger-signal bydiverting the actuating-current from the electro-magnet during the timeoccupied by the train in traversing the section guarded by said signal,and a circuit-breaker controlled by the moving train, which acts tocontinue the exhibition of said danger signal by interrupting thecurrent through its electro-magnet during the time oc cupied by thetrain in traversing a determinate portion of the next succeedingsignal-section.

4. The combination, substantially as hereinbet'ore set forth, of aseries of two or more normally-closed railway-signaling circuits and aseries of circuit-breakers, one for each circuit, each of whichcircuit-breakers is actuated or controlled by an electro-magnet included in the next circuit in the series.

5. The combination, substantially as hereinbefore set forth, of abattery, a section of railway-track, consisting of two parallel lines ofrails insulated from each other, each of which constitutes part of thecircuit traversed by the current of said battery, two electro-magnetsincluded in said circuit, and a circuit-closer which acts simultaneouslyupon both electromagnets by diverting the current from one of them, andthereby increasing the strength of current traversing the other.

Signed by me this 9th day of August, A. D. 1880.

OSCAR .GASSETT.

W'itnesses:

ISRAEL FISHER, FRANK L. POPE.

